Optical comb frequency-controlled by rotating polarization state

We report a control method to stabilize frequencies of a nonlinear polarization rotation mode-locked laser by tuning polarization state with a home-made intra-cavity electro-optic modulator (EOM). The EOM rotates polarization state about 1.2 × 10⁻⁴ rad/v in ellipticity, and enables wide range frequency control of carrier-envelope-offset frequency (fceo) or repetition rate (fr). By stabilizing the fr, fceo and a comb teeth @ 1550 nm with the EOM respectively, we obtain that frequency control dynamic ranges increase at least one order in comparison with the traditional intra-cavity EOM technique. In additional, this technique exhibits less side-effect than traditional frequency control methods.